The Effect of Long-Term Oxygen Therapy on 6-Minute Walking Distance, Clinical Parameters, and Hemodynamics in Patients with Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension: A Prospective, Randomized, Controlled Trial (Sopha Study)

ABSTRACT

Current recommendations suggest oxygen (O2) supplementation in patients with pulmonary hypertension (PH). The effect of long-term O2 administration has not been investigated much among these patients. Thus, the aim of this study is to investigate the effect of long term O2- treatment in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) on exercise capacity, clinical parameters and hemodynamics. In this prospective, randomized, controlled trial, 20 patients with PAH or CTEPH under stable PH therapy experiencing oxygen desaturations at rest and/or during physical activity will be randomized to receive oxygen or standard of care (SoC) for 12 weeks. To patients receiving SoC, O2 therapy will be offered after 12 weeks (cross-over design). The primary endpoint is the change in the distance walked in 6min after 12 weeks of treatment. Secondary endpoints include change in clinical parameters and hemodynamics. Overall, 20 patients (O2 n=10 vs. SoC n=10) are planned to participate. So far, 12 patients have already been randomized and nine have completed the study. Two patients died, one patient owing to SARS-CoV2 pneumonia in the oxygen arm and one owing to right heart failure in the SoC arm. So far, the O2 therapy is being well tolerated by all patients. Further results are expected in due course. The study is expected to complete recruitment by the end of September 2022. Oxygen therapy is well tolerated. Further results are expected soon. The effect of long-term oxygen supplementation should be investigated further in larger controlled trials.